
Doc. No.: OMS500000104
Rev: A Page 36 of 42
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12.0
Trouble-Shooting Pumps
This chart is designed to aid in the solution of pump and pump system problems. Once the
problem has been identified, work through the possible causes and solutions until the problem
has been corrected.
No flow from pump
−
Tank is empty
−
Inlet valve is closed
−
Inlet strainer is clogged with debris
−
Crankshaft is not turning
Insufficient pressure from pump ONLY
−
Pump speed is too slow
−
Relief valve improperly adjusted and by-passing fluid
−
Oversize or worn nozzle on equipment
−
Worn pump valves
−
Excessive leakage from pump seals
Insufficient flow from pump ONLY
−
Pump speed is too slow
−
Relief valve improperly adjusted and by-passing fluid
−
Worn pump valves
−
Excessive leakage from pump seals
Insufficient flow OR pressure AND rough operation
−
Valve problem:
1.
Pump valve stuck in open or closed position
2.
Valve assembly is damaged or unseated
3.
Valve seat is washed out
−
All pump cylinders not primed
−
Inlet strainer is clogged with debris
−
Excessive gas in liquid due to:
1.
Air leaks in suction line or fittings
2.
High spots in suction line that allow formation of gas
pockets
3.
Vortex in tank near inlet pipe opening
−
Pump is cavitating due to:
1.
Insufficient NPSHa (tank head or charge pressure)
2.
Fluid viscosity is too high
3.
Inlet line is too long and/or too small diameter